Gaseous electric discharge lamp device



Dec. 18, 1934. P|RAN| ET AL 1,984,429

GASEOUS ELECTRIC DISCHARGE LAMP DEVICE Filed July 21, 1933 INVENTORSPatented Dec. 18, 1934 I UNITED STATES PATENT OFFICE GASEOUS ELECTRICDISCHARGE LAMP DEVICE Marcello Pirani, Berlin-Wilmersdorf, and MartinReger, Berlin, Germany, assignors to General Electric Company, acorporation of New York Application July 21, 1933, Serial No. 681,592 InGermany August 1-9, 1932 5 Claims. (01. 176-122) The present inventionrelates to gaseous elecused in the device. Since high current densitiestric discharge lamp devices generally and more can be used in this typeof gaseous electric disparticularly the invention relates toimprovecharge lamp device it is possible to vaporize in ments inconcentrated light sources useful in conthe lamp metals having avaporization tempera- 5 nection with television, sound reproduction,specture of over 500 C., such as alkali earth metals 5 trometry andsimilar arts. I which vaporize at a temperature of between 600- Theobject of the present invention is to pro- 800 C. as well as metalshaving a lower vaporizvide a gaseous electric discharge lamp device ingtemperature, such as mercury. The vaporwhich is a concentrated,brilliant, uniform, high ized metal is then present in the gaseouselectric intensity point light source. Another object of discharge pathand the spectrum of the light 10 the invention is to provide such a lampdevice emi ted by t e a p s strong in t y c a startable and operable oneither alternating or aeteristie 0f the metal p When Such metal directcurrent. A further object of the invention V p are d in the l p Weprefer to use a is to provide a lamp device of the above type Startinggas,s11eh as argon, at a pressure pp 15 wherein high current densitiescan be used. A ciably a r a tha of t -m al vapor p sfurther object ofthe inventi n i t provide sure in order to reduce the rate of difiusionof gaseous electric discharge lamp device of the the metal v p r throughthe Op n n in he housabove type wherein the vapor of difficultly vapor-Ving to a minimum. Bafiles are also used for this izable metals, such assodium, constitutes the gasp p w d s d- The m l housing ateous fillingor is a component of the gaseous filltains at the highest a dull redtemperature and 20 ing. A still further object of the invention is todoes not emit light of an intehsitytwhieh wou d i provide su h a lamp di of simple Structure mix with the light emitted by the gaseous elecandthe manufacturing cost of which is reduced tric discharge in he v Thhousing is pto a minimum. Further objects d advantages arated from thewalls of the glass container of attachi t th d i and t use Operation thedevice so that said glass walls of the container 25 will be apparent tothose skilled in the art from do t attain a dan r us t mp atu e du thefollowing particular description. the Operation of the device- Theinvention attains its objects by providing In the drawing a c mpanyinand formin part a metal housing in the glass container of a gasof thisSpecification W b d ts of the in- 0 eous electric discharge lamp devicecompletely vention are shown in which enclosing th gaseous 1 tridischarge. The Fig. 1 is a side elevational view of one emboditerior ofsaid housing is divided by a wall having ment of the invention. acommunicating passage therein. A th iem Fig. 2 is a similar view of thesame embodiment electrode is mounted on each side of said wall m thePOSitiOn shown in 1, and

5 in said housing out of line with the passage in Fig. 3 is'a sideelevational view of another emsaid wall. The light emitted by thegaseous elecbodiment of the Inventiont discharge passes through anopening in said Like numbers denote like parts in all the figures.housing co-axial with the communicating pas- Referring to Figs. 1 and 2of the drawing the sage in said wall, and the gaseous electric disnewand W lamp Flevlce compnses a bulb like charge in the device is viewedend on through said glass contamer 1 haYmg m Current least 40 opening Aconcentrated, high intensity light 4 and 5 are sealed into the pinchpart 3 of said spot of great surface brightness and uniformity stem 2 nelgctrodes 10 and 11 mounted on is thus made available for use in thearts generthe ends of sald.leads 4 and said leads and ally. When thewall dividing the metal housing 5 *P m tubes 17 and i i is of metal itwill be understood of course that of insulating material, such asmagnesium oxide,

the potential applied to the device is greater than prevent an electncdlscharge between said leads 4 and 5 and to insulate said leads 4 and gj ?25 2 53; gggi g ggggg gfggg i figg z 5 from the walls of a metalhousing 6 mounted take place between the electrodes and the walls m Samcontamer said housmg 6 is of tangular shape and is made of sheet metal.0f the hOusmg- The gaseous electl'lc dlschm'ge Supports 7 and 8 fusedinto the pinch part 3 then follows a Pa h through the communicating ofsaid stem 2 are provided for said housing p a e i the partition- A pdevice having 6. The space in said housing 6 is divided into the abovestructure is easily and in Ypensively two parts by a diagonal wall 9 ofsheet metal 5 manufactured and high current densities can be and one ofsaid electrodes 10 and 11 is located 10 12 and which is indicated at 13.

in each of said parts. Said electrodes 10 and 11 are electron emittingwhen heated and comprise a metal filament, such as a tungsten filament,coated with an electron emitting material, such 5\ as barium oxide. Acylindrical tube 12 of small internal diameter pierces said partition 9to form a communicating passage between the two parts of said housing 6.The top wall of said housing 6 has an opening therein co-axial with saidtube Said thermionic electrodes 10 and 11, which operate at anincandescent temperature, are out of line with said tube 12 and are notvisible through the opening indicated at 13. The discharge path between5 said electrodes 10 and 11 goes through said tube 12 when the potentialapplied across the electrodes 10 and 11 is greater than the combinedanode and cathode potential drop of a discharge between said electrodes10 and 11 and the walls of said housing 6 and the gaseous electricdischarge is concentrated in said tube 12. The part of the gaseouselectric discharge located in said tube 12 is visible end-on through theopening "13 and is a concentrated, brilliant, uniform, high intensityspot, or point source of light. The

gaseous electric discharge is completely surrounded by the housing 6.

Said container 1 is filled with a rare gas, such as argon or neon, ata'pressure of approximately 1-10 mm. When desired, a vaporizablematerial,

particularly important where an alkali metal vapor, such as sodiumvapor, is used as a component of the gaseous filling toprotect the glasscontainer from the chemical effects of such vapor. Said container 1 ismade of a glass resistant to 5 the chemical efiects of the alkali metalvapor,

when desired. The gaseous electric discharge between said electrodes 10and 11 first takes place in the rare gas. The gaseous electric dischargeraises the temperature of said housing 6 and the vaporizable metalcontained in said housing 6 to the vaporization temperature of the metaland the metal is then present in vaporous form in the discharge pathduring the operation of the device. The spectrum of the light emitted bythe device is rich in rays characteristic of the metal vapor dur-' ingthe operation of the lamp device. The housing 6 is separated anappreciable distance from the walls of container 1 which protects saidwalls from the heat of the gaseous electric discharge during theoperation of the lamp. High current densities necessary to generateenough heat to.

70 bodiment the partition 9 is vertical and the electrodes 10 and 11 arein the same horizontal plane. The tube 12 is located above saidelectrodes 10 and 11 and-the longitudinal axis thereof is parallel tothe plane of said electrodes. The ends of 7 said tube 12 extend beyondsaid electrodes 10 and 11. A tube 14, which is co-axial with said tube12, protrudes from one of the side walls of said housing 6 and acts as abaffle for the particles of vaporized material in said housing to retardthe rate of diffusion. of the metal vapor from the housing 6 tocontainerl. The glass walls of said container 1 are thus kept free fromundesired light absorbing deposits of condensed material and said wallsare protected from the chemical efiects of the vapor filling. Thegaseous electric discharge is visible through the opening in said tube14 and is a concentrated, bright, intense, uniform spot of light. Aring-shaped electrode 15 mounted on current lead 16 sealed into thepinch part 3 of said stem is adjacent the external end of said tube 14and is concentric with the longitudinal axis of said tube 14. Saidelectrode 5 is connected as an auxiliary starting electrode when theelectric discharge device is operated on alternating current and as ananode when the device is operated on direct current, when desired.

While we have shown and described and have pointed out in the annexedclaims certain novel features of the invention, it will be understoodthat various omissions, substitutions and changes in the forms anddetails of the device illustrated and in its use and operation may bemade by those skilled in the art without departing from the broad spiritand scope of the invention, for example, any of the well known types ofthermionic electrode, such as the oxide coated, metal shell-type Hullelectrode, or the mixed, sintered metal and oxide type Pirani electrode,can be used in place of the electrodes 10 and llashown and described.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, a housing in saidcontainer, a vaporizable material in said housing, said housing beingdivided into chambers by a partition having a communicating passage ofappreciable length therein, one of said electrodes being mounted in eachof said chambers, and one of the walls of said housing being perforatedin line with said communicating passage, the end of said passage beingat an appreciable distance from the opening in said housing.

2. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, a housing in saidcontainer, 9. vaporizable material in said housing, said housing beingdivided into chambers by a partition having acommunicating passage ofappreciable length therein, one of said electrodes being mounted in eachof said chambers, out of line with said passage and one of the walls ofsaid housing being perforated in line with said communicating passage,the end of said passage being at appreciable distance from the openingin said housing.

3. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, a housing in saidcontainer, a vaporizable material in said housing, said housing beingdivided into chambers by a partition having a communicating passage ofappreciable length therein, one of said electrodes being mounted in eachof said chambers, a tube in the wall of said housing co-axial with saidcommunicating passage and spaced an appreciable distance from the end ofsaid passage.

4. An electric discharge device comprising a women container, electrodessealed therein, a gaseous atmosphere therein, a housing in saidcontainer, a vaporizable material in said housing, said housing beingdivided into chambers by a partition having a communicating passage ofappreciable length therein, one of said electrodes being mounted in eachof said chambers, a tube in the wall of said housing co-axial with saidcommunicating passage and spaced an appreciable distance from the end ofsaid passage, another of said electrodes being mounted outside of saidhousing and adjacent the external end of said tube.

5. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, a housing in saidcontainer, said housing being divided into chambers by a. partitionhaving a communicating passage of appreciable length therein, one ofsaid electrodes being mounted in each of said chambers, and one of thewalls of said housing being perforated in line with said communicatingpassage, the end of said passage being at an appreciable distance fromthe opening in said housing.

ELLO

